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Kooks LTH Questions

Now that I am going to pull the trigger on Kooks LTH's, I need to pick size and accessories. I have read a ton of posts and they all seem to point to 1-7/8" but I was thinking 1-3/4". Any reason I should go with the larger tubes? Do I need gaskets or do the Kooks provide a quality set? How about fasteners? I saw blacksheep-1 didn't like Stage 8's but others swear by them. I will be dropping the K-member so I will have good access.
 
I have the 1-7/8" and they're been on the car for 5 years now and no problems.
I used new OEM gaskets. The one that came with Kooks didn't look that great. Go to your dealership so you don't have to worry about them being bend during shipping. Mine also price matched the online price.
I also used the Stage 8 bolts and they're fine.

If you don't reuse the factory studs, make sure you get new bolts with the correct pitch. There is 2 different pitch depending on the year. Your best bet in finding the pitch is to pull one of the stud and measure it.
My Kooks came with 2 set of bolts and none of them matched my heads.
 
I guess I will have to decide size. I would think that the 3/4 would give me a little more room to work. I have no motor mods so I don't think I need the largest tubes anyway. As for studs......I plan on reusing the stockers so I won't have to worry about screwing it up.
 
I believe the race teams use the 1 7/8 headers. Never seen anyone complain about using them. I’d follow @Swiss Boss lead on this.
 

Mad Hatter

Gotta go Faster
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2,504
Santiago, Chile
I got my 1 3/4 LTH Kooks headers a while back because Shaun at AED said that if you will not boost the engine then he saw no point. Since then I have seen that quite a few people have gone to 1 7/8 and for my buddies cars I have gotten 1 7/8 with no problems and good results. If I had the choice again, I would get the 1 7/8 just to keep the options open in the future.
 
Yeah i went with 1-3/4 for my street car. I wanted to help supplement the lack of the slightly lower tq of the boss intake manifold. It rev's and makes plenty of power up high, but i could tell a its a bit softer on the low end. I didnt see a couple of ponies up top that i only occasionally experience being worth the cost of a bit of needed tq.

also ginx on me for posting a similar thread asking similar questions after this one
 

Mad Hatter

Gotta go Faster
4,001
2,504
Santiago, Chile
For me the 1 3/4 Kooks gave a big boost in the lower middle end. Last time I went to the Dyno i was stock with just the kooks.. My peak Torque was 380 at 3500 rpm! Very useful!! (peak hp was 403 at 7000rpm) So the LTH was good for some 30Hp and big torque boost at 3500 of almost 50.
 
That's what my thought process was with the 1 3/4 tubes. I know the 7/8 would work but I have no plans for any big power boosting with the Boss. Definitely not forced induction. Doubt I will even change the intake as I just feel the stock airbox works pretty well. So the 3/4 should be just fine.
 

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